From 8a0efa53e44919bcf5ccb1d3353618a82afdf8bc Mon Sep 17 00:00:00 2001 From: Christopher Faylor Date: Thu, 17 Feb 2000 19:39:52 +0000 Subject: import newlib-2000-02-17 snapshot --- newlib/libc/string/strcat.c | 104 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 104 insertions(+) create mode 100644 newlib/libc/string/strcat.c (limited to 'newlib/libc/string/strcat.c') diff --git a/newlib/libc/string/strcat.c b/newlib/libc/string/strcat.c new file mode 100644 index 000000000..411eadb85 --- /dev/null +++ b/newlib/libc/string/strcat.c @@ -0,0 +1,104 @@ +/* +FUNCTION + <>---concatenate strings + +INDEX + strcat + +ANSI_SYNOPSIS + #include + char *strcat(char *<[dst]>, const char *<[src]>); + +TRAD_SYNOPSIS + #include + char *strcat(<[dst]>, <[src]>) + char *<[dst]>; + char *<[src]>; + +DESCRIPTION + <> appends a copy of the string pointed to by <[src]> + (including the terminating null character) to the end of the + string pointed to by <[dst]>. The initial character of + <[src]> overwrites the null character at the end of <[dst]>. + +RETURNS + This function returns the initial value of <[dst]> + +PORTABILITY +<> is ANSI C. + +<> requires no supporting OS subroutines. + +QUICKREF + strcat ansi pure +*/ + +#include +#include + +/* Nonzero if X is aligned on a "long" boundary. */ +#define ALIGNED(X) \ + (((long)X & (sizeof (long) - 1)) == 0) + +#if LONG_MAX == 2147483647L +#define DETECTNULL(X) (((X) - 0x01010101) & ~(X) & 0x80808080) +#else +#if LONG_MAX == 9223372036854775807L +/* Nonzero if X (a long int) contains a NULL byte. */ +#define DETECTNULL(X) (((X) - 0x0101010101010101) & ~(X) & 0x8080808080808080) +#else +#error long int is not a 32bit or 64bit type. +#endif +#endif + +#ifndef DETECTNULL +#error long int is not a 32bit or 64bit byte +#endif + + +/*SUPPRESS 560*/ +/*SUPPRESS 530*/ + +char * +_DEFUN (strcat, (s1, s2), + char *s1 _AND + _CONST char *s2) +{ +#if defined(PREFER_SIZE_OVER_SPEED) || defined(__OPTIMIZE_SIZE__) + char *s = s1; + + while (*s1) + s1++; + + while (*s1++ = *s2++) + ; + return s; +#else + char *s = s1; + + + /* Skip over the data in s1 as quickly as possible. */ + if (ALIGNED (s1)) + { + unsigned long *aligned_s1 = (unsigned long *)s1; + while (!DETECTNULL (*aligned_s1)) + aligned_s1++; + + s1 = (char *)aligned_s1; + } + + while (*s1) + s1++; + + /* s1 now points to the its trailing null character, we can + just use strcpy to do the work for us now. + + ?!? We might want to just include strcpy here. + Also, this will cause many more unaligned string copies because + s1 is much less likely to be aligned. I don't know if its worth + tweaking strcpy to handle this better. */ + strcpy (s1, s2); + + return s; +#endif /* not PREFER_SIZE_OVER_SPEED */ +} -- cgit v1.2.3